Step stool



FIG. 1 is a perspective view of the step stool;

FIG. 2 is an upper plan view of the step stool;

FIG. 3 is a front elevation of the step stool;

FIG. 4 is side elevation view of the step stool, the other side being a mirror-image, thereof; and,

FIG. 5 is a rear elevation of the step stool. 

The ornamental design for a step stool, as shown and described. 